Door closure apparatus



Filed Sept. 15. 1960 2 Sheets-Sheet l JOHN L. FISHER INVENTOR.

mm 0% mw ATTORNEY Sept. 10, 1963 Filed Sept. 15, 1960 FIG. 4.

J. L. FISHER DOOR CLOSURE APPARATUS FIG. 3.

2 Sheets-Sheet 2 JOHN L. FISHER INVENTOR.

ATTORNEY United States Patent 3,163,034 D983 ULOSUEE APPARATUS iohn i2.Fisher, Buena Paris, Caiifu, sssignor of one-third to Russell 8.Robinson, Newport Beach, (Iaiih, and onethird to Harvey C. Nienow, SantaAna, Calif.

.Fiied Sept. 15, 196i), Ser. N 56,149 7 (Iiaims. CE. ld-fid) The presentinvention relates to door closure apparatus, but more particularly tomeans for controlling the rate of closure of a sliding door.

Although many satisfactory types of door closing apparatuses have beendevised for controlling the rate of closure of hinged doors, such hasnot been true with respect to sliding door wherein the problems areconsiderably different. Mechanisms heretofore employed for returningsliding doors to their initial closed positions have been eitherineffective in returning the door the entire distance or have returnedthe door at a variable rate of speed. Either of these conditions islikely to pose a serious threat of injury to persons using the door,particuiarly small children. Also, devices heretofore prevalent in theart have been very bulky and cumbersome in construction, and have leftmuch to be desired regarding satisfactory operation over a reasonableperiod of time.

In view of the above shortcomings, the present invention has as one ofits objects the provision of a door closure apparatus which is simpleand compact in construction, and rugged and dependable in operation.

Another object of this invention is to provide a door closure apparatuswhich is capable of returning a sliding door to its closed position at asubstantially constant rate of speed.

Another object of this invention is to provide such a door closurepparatus which is capable of returning a sliding door from its fullyopen to its fully closed position.

Another object of this invention is to provide a door closure apparatusas characterized above which employs both spring means and pneumaticmeans.

Another object is to provide apparatus as characterized above which isadapt-able for use on sliding doors which are'required to moveaconsiderable distance from their open to their closed position.

Another object is to provide a door closuremechanism as characterizedabove wherein is employed a preformed spiral spring which is verycompact and diminutive in construction as compared to the overall lengththereof when fully extended.

Another object of this invention is to provide apparatus ascharacterized above wherein the spring means is a coil spring which ispre-wound to thereby be self-biased toward its wound position andwherein each successive increment or unit of length of the spring isprovided with substantially the same bending force.

Another object is to provide door closure apparatus as characterizedabove wherein the coil spring is so utilized that at any given momentthroughout the opening or closing movement of the door only oneincrement or unit of length of the spring is effective to bias the doortoward its closed posit-ion whereby such door is urged toward its closedposition with the same amount of force regardless of the instantaneousposition thereof.

Another object is to provide apparatus as characterized above wherein isincluded manual means for adjusting the rate of return of the door fromits open to its closed position.

Another object of this invention is to provide door closure meanscomprising the above spring means and also including a hermeticallysealed chamber having a movable wall portion which is so associated withthe 3,103,034 Patented Sept. 10, I963 door closure means that the rateof closure of the door is governed by the action of such wall portionagainst the fluid pressure within the hermetically sealed chamber, therebeing adjustable bleed means provided for controlling the rate of fluidflow to and from such chamber.

The novel features Which I consider characteristic of my invention areset forth with particularity in the appended claims. The device itself,however, both as to its organization and mode of operation, togetherwith additional objects and advantages thereof, will best be understoodfrom the following description of a specific embodiment when read inconnection with the accompanying drawings, in which FEGURE l is a sideelevational view of a sliding screen door having the subject doorclosure apparatus attached thereto;

FIGURE 2 is a longitudinal sectional view of the door closure apparatusof FIGURE 1, showing the door in its closed position;

FIGURE 3 is a sectional view taken substantially along line 3-3 ofFIGURE 2;

FIGURE 4 is a longitudinal sectional view of the subject apparatus,showing various of its component parts in their extended positionsfollowing movement of the door to its fully position; and

FEGURE 5 is an exploded perspective view of the parts which comprise theplunger mechanism employed in the subject invention.

Like reference characters indicate corresponding parts throughout theseveral views of the drawings.

Referring to FIGURE 1 of the drawings, it shows a screen door It} whichis provided with appropriate metal or plastic rollers (not shown) forenabling door 10 to he slid back and forth between its open and closedpositions. Door It? comprises a door casing or frame 12 and screenmaterial 14 attached to said frame in any well known manner. As will bereadily apparent from a further understanding :of the present invention,door frame 12 may be made in any desired configuration and of anyappropriate material, and the screening material 14 may be replaced withglass, wood, or any other desired material Without departing in anyrespect from the pertinency of the instant invention. Door id is shownin FIGURE 1 in its closed position whereby a portion of frame 12 abutsagainst a door jamh 16.

Door closure apparatus 18 is secured to door frame 12 by means ofseveral screws 20, 2d, and a portion of the apparatus :18 is secured tothe door jamb 16 or the wall immediately adjacent thereto by means of ascrew 22, which is more clearly shown in FIGURES 2 and 4.

As shown in FIGURE 2, door closure apparatus 18 comprises a housing 24formed with a central cavity or chamber 26, there being an opening 28communicating with chamber 26. Housing 24 is provided with a removableend wall 24a which is held in its assembled position by screws 30. Toassist in hermetically sealing chamber 26 for purposes hereinafter to beexplained in detail, a sealing gasket 32 is interposed between end wall24a and the main portion of housing 24.

Firmly fastened to housing 24 within opening 28 is a hollow or tubularmember 34. In the interest of hermetically sealing chamber 26 it hasbeen found preferable to secure end portion 34a of tube 34 withinopening 28 of housing =24 by means of bonding material such as epoxyresins. Slidably engaging the other end 34b of tube 34 is a mountingbracket 36 which has a suitably formed opening 36a for receiving end 34band a centrally located through opening 36b for slidably receiving abody member 38 which may be tubular in form as shown in the drawings.Bracket 36 is secured to frame 12 of door 10 by a screw 20. External end33a of tube 38 is fastened as by a Q means of rivet it} to a mountingbracket 42 which is connected to door jamb 16, or to the adjoining wallportion,

by'means of screw 22. Fixed to end 331) of tube 33 is a 1 in theirassembled positions.

Referring to'FlGURE of the drawings, it will be seenthat each of washer48 and retaining ring 5%} is provided with a through opening wherebythey may he slipped over end portion 46b of plug 46 prior to insertionof such plug into the end 3812 of tube 38. It will also be noted thatthe peripheral portion of annular shoulder 46a of plug 46is rounded forbetter cooperation with leather washer dd in hermetically sealingagainst the inner surface of hollow tube 34-. 1

Positioned within chamber of housing 24 is preformed spirally woundspring member 54 having an end 54a attached to plug 46 by insertionthereof within a slot 460 formed in' the latter, there being a rivet orscrew 56 for retaining spring end portion 56a in such position. Spring54 comprises flat spring steel or other spring material which has beenwound about a mandrel or other tool having a fixed axis to therebyprovide a spirally wound coil spring which is self-biased toward itswound position. In forming such spirally wound spring 54-, eachsuccessive increment or unit of length of spring material is formed withsubstantially the same radius of curvature and hence is provided withsubstantially the same bending force. As will be readily appreciatedfrom an understanding of the operation of the instant invention, it isthis bending force which biases the spring toward its Wound position,

and it is this force which is used in returning sliding door It to itsclosed position as will hereinafter appear.

As most clearly shown in FIGURE 3, unique mounting means is provided forpositioning spring 54 within chamber 26. Such mounting means comprises apin 58 formed of relatively hard stainless steel or other suitablematerial and provided with a reduced central portion 5811. Pin 58 isfurther provided with cylindrical end portions 535 and 580 each of whichis formed with a shoulder 58d and 58 2 respectively for engagement withelongated abutments 24b and 240 formed in the opposite side walls ofhousing 24. Rotatably mounted on pin 5% 'is a roller 60 the oppositeends of which are provided with bosses 60a and 69b which engage theopposite side walls of chamber 26. The reduced central portion 58a or"pin 5% enables roller 60 to rotate on and about pin 58 in asubstantially frictionless manner, the bosses 60a and 6% also minimizingfrictional forces during rotation of roller 65). Spring member 54 may bepre-formed about roller fill, or it may be pre-formed about a mandreland subsequently mounted on roller 64}. Once this has been accomplished,pin 58 is inserted within the through opening of roller-o0 and such'subassembly is then inserted into chamber 26 while endwall 24a ofhousing 2 is removed.

It should be noted that once the spring assembly is properly mountedwithin cavity 26, it is free to move in a vertical direction while beingprevented from moving in a horizontal plane. This arrangement is verydesirable if not mandatory to insure satisfactory operation of thedevice. As the spring material is unwound from coil 54, the outerdiameter thereof decreases appreciably. If the axis .of rotation of coilspring 54 is stationary during this period, several undesirable effectswill result.

Firstly, as the coil diameter decreases there is a greater tendency forthe spring material within hollow member 34 to rub against or engage theside walls of member S lhas been shifted downwardly with respect tomember 34. This creates very undesirable extraneous frictional forceswhich hinder satisfactory operation of the door closure apparatus. Also,if after the door is opened the remaining coil is so positioned that thecenter-line of movement of member is not tangent with such coil 54, thenthe entire biasing force of spring 54 is not available for moving doorin to its closed position. I To state it another way, if such tangentialrelationship does not exist then biasing force of spring 54 has both avertical and a horizontal component, only the latter of which iseffective for moving door lit to its closed position. It is thisvertical force component which automatically moves the spring E l up ordown, as the case may be, to insure that the center-line of member 38 istangent to the coil 54. Such movement of spring 54 is accomplished bythe sliding of pin 53 along shoulders 24b and 24c in the side walls ofhousing As will hereinafter appear in greater detail, the above featureinsures that all of the biasing force or" spring means is applied toreturning doorlh to its closed position and since said spring is formedwith a constant spring rate, a constant force is thereby applied to doorit? regardless of its position.

An adjustable bleed control 62 is provided in housing 2 for cooperationwith plunger mechanism 44. Bleed control 62 can take virtually anydesired form, but is shown in the instant embodiment as comprising athreaded needle valve 64 fastened within a threaded opening 24d inhousing 24. The pointed end 64a of needle valve 64 cooperates with ableed port 242 and an exhaust port 24 formed in housing 2% as shown inFIGURES 2 and 4. A lock nut 66 is provided on needle valve 64 forretaining said needle valve in any selected position.

Loosely engaging body member or tube 38 is a crimped lock Washer 63which, when the door in is in an open position, may be manually movedinto engagement with mounting bracket 36 merely by sliding said washer68 along tube 38. While in this position, any force tending to move doorlit to its closedposition will, due to the bent nature of washer, 68cause such washer to bind with tubular member 33. As such Washer 68overcomes the force tending to close door llti whereby the latter isretained in its pro-selected open position.

The embodiment chosen for illustration of the instant inventiongenerally operates as follows:

With spring means 5'4 pre-forrne'd such that each successive incrementor unit of length of the spring material is formed with the same bendingforce, it will be seen that as door llltl is moved from its closedposition, shown in FIGURE 2, to an open position as illustrated inFIGURE 4, spring 54 creates a constant force opposing such movement.Such movement of door it) causes relative movement between telescopingtubular members 34 and 38 whereby spring member 54 is unwound to anextent corre sponding to such relative movement.

Also opposing movement of door it? to its open position is the pneumaticmeans comprising the hermetically sealed chamber 26, bleed means 62 andthe plunger mechanism 44 the latter of which employs leather washer 48in sealing engagement with the through openingof tubular mem her 34. Asplunger mechanism 44- is. moved away from housing 24-, a partial vacuumis created within chamber 26 in accordance with the setting of needlevalve 64.

Upon release of door 10 while in its open position, spring means 54 inattempting to return to its pre formed coiled position urges such doorto its closed position. It should be particularly noted however that theonly segment or increment of the spring material which is, at any givenmoment, exerting a force in the proper direction for closing door it) isat segment immediately adjacent the'coil as shown at 54b. That is,although energy is stored in each and everyincrement of spring materialwhich has been straightened during openmovement of the door, only thesegment of spring material which is already partially wrapped around thecoil is able to create a force which is in the direction of relativemovement of tubular members 34 and 38. The energy which has been storedin the straight portion of the spring material within tubular member 34creates a force trying to return such spring portion to its pro-formedarouate condition, but such force acts in a direction perpendicular orlateral with respect to the direction of telescoping movement of members34 and 38. Thus, such force has no eifect whatever on tending to closedoor 10. It is because of this phenomenon that it has been found that ifeach successive increment or unit of length of spring material ispre-formed with the same bending force, a constant force will be exertedby spring 54 in urging door it) towards its closed position throughoutthe entire movement of the latter from its fully opened position to itsclosed position. This will be so regardless of the length of spring 54and regardless of the movement of the sliding door.

As will be readily apparent to those persons skilled in the art, thebiasing force of the portion 54b of spring material will always bepresent during opening and closing of the door and it is this forcewhich raises and lowers the spring member 54 as hereinbefore explained,to keep the unwound portion of the spring material in direct alignmentwith the direction of telescoping of members 34 and 38. This obtains byvirtue of the fact that the force created by the increment of springmaterial at 54b acts directly toward the end 54a of spring member 54. Assuch, this force will tend to maintain the distance between point 541)and the end portion 54a of sprin material 54 as short as possible,thereby causing the unwound portion of the spring material to mignitself perpendicularly with respect to the bosses or shoulders 24b andMe of housing 24. Thus, as the spring material is being unwound fromroller 60, pin 58 will move upwardly and while the spring material isbeing returned to the spool or roller 60 the entire coil will movedownwardly.

It will be noted that this arrangement further insures that only thatportion of the spring material at point 54b is capable of urging thedoor to its closed position, the other energy stored in the unwoundportion of the spring material being truly at right angles with respectto the direction of telescoping relative movement of the tubular members34 and 38. If such arrangement was not provided for permitting the coilto move up and down in accordance with the movement of door It theforces created by the unwound spring material within tubular member 34would have a component in line with the direction of telescopingmovement of members 34 and 38, which components would add to or subtractfrom the spring force in increment 54b acting on door 16.

During closure of door It the fluid pressure within chamber 26 increasesin accordance with the adjustment of bleed means 62. As will be readilyrealized, this increase in pressure within chamber 26 is due to theclosing movement of sealing washer 48 within tubular member 34. Thus therate oft" return of door 10 to its closed position will be determined.by the setting of needle valve 64 of bleed means 62. Lock nut 66 isprovided to maintain needle valve 64 in its preselected position.

It is contemplated within the scope of this invention that the entiredoor closure apparatus could be installed within the frame 12 of door10. Under these conditions some of the various parts, particularlyhousing 24 and hollow member 34, could be eliminated and portions of theframe 12 substituted therefor.

It is thus seen that the present invention provides door closureapparatus which is simple in construction, and rugged and dependable inoperation. Such apparatus provides a constant rate of return of thesliding door to its closed position which, together with the feature ofbeing able to control the rate of return, materially decreases thelikelihood of anyone being injured due to fast or erratic returnmovement of (the door.

Although I have shown and described certain specific embodiments of myinvention, 1 am [fully aware that many modifications thereof arepossible. My invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior are and by the spirit of theappended claims.

I claim:

1. Door closure apparatus comprising, a housing formed with a cavity, acoil spring within said cavity com.- prising a strip of spring materialpro-formed such that each successive increment of spring materialpossesses substantially the same bending force, a body member fixed tosaid spring and movable relative to said housing to thereby unwind aportion of said spring material into a single plane for biasing saidbody member toward a given position relative to said housing, and meansmounting said spring within said cavity including means permitting saidcoil spring to move transversely of said plane to retain said coilspring tangent to said plane regardless of V the amount of springmaterial unwound therefrom to thereby insure that the bending force ofonly one increment of said spring material is effective at a givenmoment for biasing said body member toward said given relative position.

2. Door closure apparatus comprising, a housing formed with a cavity, acoil spring within said cavity comprising a strip of spring materialpreformed such that each successive increment of spring materialpossesses substantially the same bending force, a body member fixed tosaid spring and movable relative to said housing to thereby unwind aportion of said spring material into a single plane for biasing saidbody member toward a given position relative to said housing, and meansmounting said spring within said cavity including means operable underthe biasing force of said coil spring to move the latter in a di ectiontransverse to said plane to cause said coil spring to retain itselftangent to said plane regardless of the amount of spring materialunwound therefrom to thereby insure that the bending fiorce of only oneincrement of said spring material is effective at a given moment forbiasing said body member toward said given relative position.

3. Door closure apparatus comprising, a housing formed with a cavity, acoil spring within said cavity comprising a strip of spring materialpr-e-lformed such that each successive increment of spring materialpossesses substantially the same bending force, a body member fixed tosaid spring and movable relative to said housing to thereby unwind aportion of said spring material into a single plane for biasing saidbody member toward a given position relative to said housing, and meansmounting said spring within said cavity comprising a pin on which saidcoil spring is rotatably mounted and which is free to move in a planetransverse to the plane of said unwound spring material whereby saidcoil spring is retained tangent to the plane of said unwound springmaterial regardless of the amount of material un- Wound to therebyinsure that the bending force of only one increment of said springmaterial is effective at a given moment for biasing said body membertoward said given relative position.

4. Door closure apparatus for returning a sliding door from an open toits closed position comprising, a housing fixed to said door and formedwith an hermetically sealed chamber and an opening communicatingtherewith, an elongated hollow member having one end fixed to saidhousing within said opening, an elongated body member partially withinsaid hollow member having one end fixed to a door jarnb associated withsaid door for rectilinear movement relative to said hollow member uponmovement of said door relative to said door jamb, a sealing washer forpreventing fluid flow through said hollow member fixed to the other endof said body member for movement therewith relative to said hollowmember, adjustable bleed means in said housing for controlling the rateof fluid flow to and fnom said chamber, a coil spring self-biased to itswound position having one end fixed relative to said body member, andmeans for mounting said spring member Within said chamber comprising apin rotatably carrying said coil spring and abutment means in theopposite side walls of said chamber for engagement by said pin to retainsaid spring within said chamber while permitting movement thereoflaterally of the direction of movement of said sliding door whereby assaid door is moved from its closed to its open position said coil springis unwound a corresponding arnount to thereby store in said springmember sufficient energy for returning said door to its closed positionat a substantially elongated hollow member having one end fixed to saidhousing within said opening, an elongated body member partially withinsaid hollow member having one end fixed to a door jamb associated withsaid door for telescoping movement relative to said hollow member uponmove ment of said door relative to said door jamb, a sealing gland forpreventing fluid fiow through said hollow member fixed to the other endof said body member for movement therewith relative to said hollowmember, adjustable bleed means in said housing for controlling the rateof fluid flow to and from said chamber, a coil spring selfbiased to itswound position having one end fixed relative to said body member, andmeans for mounting said spring member Within said chamber comprising apin rotatably carrying said coil spring and abutment means in oppositeside walls of said chamber for engagement by said pin to retain saidspring within said chamber while permitting the biasing force of saidspring to move said spring in a direction normal to the direction ofmovement of said sliding door whereby as said door is moved from itsclosed to an 8 open position said coil spring is unwound a correspondingamount to thereby store in said spring member sufiicient energy forreturning said door to its closed position at a substantially constantrate in accordance with the adjustment of said bleed means.

6. Door closure apparatus comprising, a housing, a coil spring withinsaid housing formed of overlapping successive convolutions of resilientmaterial, a member fixed relative to said spring and rectilinearlymovable relative to said housing, and mounting means for said springcomprising means providing a track within said housing extendingtransversely of the direction of movement of said member and supportmeans for said coil spring operable in said track to permit of movementof said spring normal to the direction of movement of said member toinsure alignment of unwound resilient material with the direction ofmovement of said member.

7. Door closure apparatus comprising, a housing formed with a cavity, aspring member within said cavity comprising a coil of spring material,means rotatably mounting said spring member within said cavity, a bodymember fixed to said spring member and movable relative to said housingto thereby unwind said spring and store in each successive increment ofunwound spring material substantially the same amount of energy forreturn movement of said body member relative to said housing, and meansfor insuring that at any given moment only one of said increments ofspring material is effective for return movement of said body memberrelative to said housing.

References Cited in the file of this patent UNITED STATES PATENTS

6. DOOR CLOSURE APPARATUS COMPRISING, A HOUSING, A COIL SPRING WITHINSAID HOUSING FORMED OF OVERLAPPING SUCCESSIVE CONVOLUTIONS OF RESILIENTMATERIAL, A MEMBER FIXED RELATIVE TO SAID SPRING AND RECTILINEARLYMOVABLE RELATIVE TO SAID HOUSING, AND MOUNTING MEANS FOR SAID SPRINGCOMPRISING MEANS PROVIDING A TRACK WITHIN SAID HOUSING EXTENDINGTRANSVERSELY OF THE DIRECTION OF MOVEMENT OF SAID MEMBER AND SUPPORTMEANS FOR SAID COIL SPRING OPERABLE IN SAID TRACK TO PERMIT OF MOVEMENTOF SAID SPRING NORMAL TO THE DIRECTION OF MOVEMENT OF SAID MEMBER TOINSURE ALIGNMENT OF UNWOUND RESILIENT MATERIAL WITH THE DIRECTION OFMOVEMENT OF SAID MEMBER.